Fire safety glass in high-rise balconies: combining style with safety

With recent amendments to Approved Document B, the process of correctly specifying building materials for high-rise developments can often be overwhelming. Fire safety glass can be one such area that is complicated to navigate, with housing associations and local authorities looking to balance safety with aesthetics. However, thanks to technological advances, this no longer has to be the case. Here, Andy Lake, Sales Director UK & IRE from Pyroguard, explores how glass can once again be safely installed into high-rise balcony applications.

Providing safe, quality housing is a top priority, with fire safety an area of particular concern with recent industry failings. The increase in high-rise, multi-occupancy housing has propelled this topic back into the spotlight, with the critical need for local authorities and housing associations to provide safer and more comfortable spaces for their tenants to call home. As a result of this, tenants are often being provided with their own private outdoor spaces – which for high-rise applications includes balconies.

For these applications, glass is the ideal solution, able to create a striking and contemporary exterior feature, as well as encourage more natural light into the individual apartments. However, following the updates to Part B of the Building Regulations in December of 2018, a ban was placed on the use of traditional laminated glass in high-rise balconies and terraces (above 11 metres tall). This ban came after it was found that the interlayer between the laminated glass panes could melt when exposed to extreme heat (like that experienced in the event of a fire) and create combustible droplets. If these burning droplets reached terraces or apartments below, this could spread the fire further into the building.

As a result of this, housing associations and local authorities have had to find alternative non-combustible solutions for the construction of balconies, like steel. But now, with new developments on the market, glass is once again a viable option and can be re-incorporated back into high-rise balconies. However, there are a number of factors to be considered to ensure both adherence to the relevant building regulations and the safety of future tenants.

One of the most important areas to look at is the system’s ‘reaction to fire’ classification. This is denoted by an A, B, C or D rating, with either an A1 or A2 rating offering the best performance, ensuring local authorities and housing developers can be confident that the product or system they’re installing is non-combustible.

Impact resistance is another important consideration when installing safety glass, especially when looking at high-rise settings, and is measured against standard BS EN 12600. A glass with an 1A1, 1B1 or 1C1 impact rating is the recommended level. While glass is an aesthetic building product, fire safety glass is first and foremost a safety product. As a result, given the balcony application, it is essential that the glass system satisfies the required line load requirements. If a tenant was to lean or trip and fall onto the glass, it is imperative that it can hold and won’t shatter, preventing severe injury.

One further important consideration for fire safety glass in balcony applications is its UV stability. In these settings, installed on the exterior of a high-rise building, materials used will be exposed to all weather conditions, including varying levels of UV sunlight and heat. This can cause issues such as weathering, a common problem experienced by the glass and glazing industry. For example, the gel interlayers in certain products can become yellowed or hazy following long-term exposure to UV light. Here, the correct specification of products can help to protect the value invested into balconies and ensure the glass won’t deteriorate with time.

Of course, one way to guarantee quality is by looking at the test evidence available. For example, fire safety glass products should be tested to ISO 12543-4:2011 for weathering. This testing process involves placing glass samples into chambers in a controlled laboratory environment, and subjecting the sample to differing degrees of heat, humidity and UV light. Through this process, glass and glazing manufacturers can gauge a glazing system’s ability to withstand the rigours of external installation. Although it’s important to note that these tests can’t always paint a true picture. To get more accurate predictions, local authorities and housing associations should look to work with suppliers who subject their solutions to real world weathering.